Constraints such as shortages of available land when there is a need to locate a structure, either temporarily or permanently, either adjacent to land, or in a large body of water, have led to the development of floating platforms and the like that can support a structure on a body of water. For example, floating runways such as that disclosed in U.S. Pat. No. 5,906,171 provide water-borne surfaces for aircraft to land and take off, similar to surfaces on aircraft carriers. Floating airports, such as that disclosed in U.S. Pat. No. 5,398,635, can further include means for controlling the position of a floating airport by compensating for disturbances to such position by prevailing winds and currents. Complex structures, such as those disclosed in U.S. Pat. No. 5,799,603, have also been developed to provide stability under ocean conditions. According to the disclosure of the '603 patent, energy due to striking waves is partly absorbed by a buoyant load-bearing assembly that includes universal joints and shock-absorbing hydraulic cylinders.
Similarly, floating bridges and roadways have been developed for use in, for example, locations where conventional bridge construction and/or maintenance would be undesirably costly or difficult, or where a relatively short bridge span is required. The ability to transport such floating bridges to a site has been facilitated by utilizing foldable hulls, as described in U.S. Pat. No. 4,561,376, or by providing an amphibious vehicle that can be equipped with hulls and can function as a bridge or portion thereof, as described in U.S. Pat. No. 4,621,385. Such structures, while portable, are apparently somewhat complex.
It will be appreciated that in any geographic area adjacent to bodies of water, where land is scarce or not available for development, floating platforms may be desirable. Development of additional permanent or temporary facilities for manufacturing, power generation, housing or other commercial use may be desirable, but not practical in view of land use policies or community opposition. In the international context, there may be a need for facilities, such as airfields and housing facilities, for military and/or relief efforts, which cannot be located on land because of political and security concerns.
A need remains for floating structures supporting floating platforms suitable for use as aircraft landing strips, airports, roadways, bridges and off-shore facilities. A need also remains for such floating structures that are not subject to some motion caused by waves or water currents as to fail to be functional for their intended purposes. The present invention is directed to these and other objectives.